Stochastic Resonance

Abstract

Noise is often thought of as interfering with signal detection and information transmission. Static on a radio-station, ancillary conversations in a crowded room and flashing neon light along a busy thoroughfare all tend to obscure or distract from the desired information. Now, it has been realized that certain noise-induced phenomena are of great use in various contexts. One such noise-induced phenomenon which has a wide range of applications in various branches of science and engineering is stochastic resonance. Consider a double-well potential system (bistable system) driven by a weak periodic force of frequency ω. The amplitude of the external driving force is so small that there is no cross-well motion. When noise is added to the system, then at an appropriate noise intensity, a periodic switching between the two wells takes place. At this optimum value of noise intensity the signal-to-noise ratio measured at the frequency ω becomes a maximum.